<!DOCTYPE html>
<html lang="zh">
<head>
    <!--指定字符集-->
    <meta charset="UTF-8">
    <!--设定标题-->
    <title>标题和段落</title>
</head>
<body>
<h1>一级标题</h1>

<p>段落1</p>

<h2>二级标题1</h2>
<p>段落</p>

<h2>二级标题2</h2>

<p>段落</p>
<h3>三级标题</h3>
<p>段落</p>
</body>
</html>